This invention relates to interior vehicle lighting systems and lighted switch assemblies used for automotive applications.
Interior lighting systems for automotive and other vehicle applications are generally used for two purposes. One is to provide general area illumination and the other is feature lighting of specific objects, either for aesthetic or functional reasons. Traditionally, these interior lighting systems have utilized incandescent lamps for both area and feature lighting, often using lenses to control the shape and light intensity distribution of the emitted light. Although incandescent lamp systems can often be integrated into various vehicle interior trim components in a simple manner, various considerations do arise which complicates their use for automotive lighting. For example, where heat from the lamp could damage adjacent components or otherwise cause problems, thermal management of that heat must be implemented. Also, there is often little room in or behind a particular vehicle interior body panel or trim component for the lamp, socket, and lensing.
This constraint on space behind the vehicle panels can be especially true with vehicle headliners where there may be little room between the headliner and roof of the vehicle. For headliners, the solution has typically been to either require more room between the headliner and roof or to utilize a light assembly that protrudes downwardly from the headliner for a short distance. Where sufficient space is available, various functional components such as electrical conduits, lamp soffits, electrical connectors, HVAC ducts, flat speakers, and head airbags can be molded into the headliner during its manufacture. See, for example, European Patent Application EP 0979760, published Feb. 16, 2000. However, where the headliner thickness is to be kept to a minimum, the use of molded-in lamp soffits may not be practical.
The use of alternative light sources, such as electroluminescent panels, has been proposed for a wide range of vehicle lighting applications. For example, U.S. Pat. No. 4,864,473 to Tokarz et al. discloses an electroluminescent panel dome lamp designed for a convertible-type automobile. The panel is mounted on a housing that is attached to the headliner of the convertible""s roof. U.S. Pat. No. 5,013,967 to Hirotaka et al. discloses a detachable electroluminescent panel light source that can be located at various places about the inside of a vehicle to provide illumination. These locations include inside the trunk, at the glove compartment, and on the backside of the front seats. U.S. Pat. No. 5,564,813 to Curtindale discloses a sun visor that includes incandescent light sources to provide courtesy, reading, and vanity illumination. The patent states that electroluminescent lighting strips could be used in place of the incandescent lamps. However, while various automotive lighting uses of electroluminescent panels have been proposed, as exemplified by these patents, much of the prior art discloses the use of electroluminescent panels as a direct substitute for incandescent and/or LED lamps without taking full advantage of the unique structural features of the electroluminescent technology.
Accordingly, it is a general object of the invention to provide a vehicle interior lighting system that can be used to provide area or feature lighting in a manner that minimizes the aesthetic impact of the light source when not in use and that requires negligible space behind the interior body panel or trim component where the light source is located.
The present invention is directed to various interior vehicle assemblies that provide illumination using electroluminescent panels. In accordance with one aspect, the present invention is directed to a vehicle interior component assembly that includes a vehicle interior component having a fabric disposed over either a substrate or foam layer (or both). An electroluminescent panel is located between the fabric and substrate (or foam layer) and is configured to direct light from the panel through the fabric. In this way, the light source can be effectively hidden when not in use and can be incorporated into the interior component in a manner that requires little, if any, space behind the interior component. The vehicle interior component can be any of a number of different interior articles, including, for example, a headliner, door panel, vehicle seat, rear deck, sun visor, and trunk panel.
In accordance with another aspect of the invention, there is provided a vehicle carpet utilizing an electroluminescent panel, with the carpet including a substrate and a carpet pile attached to the substrate. The electroluminescent panel is mounted underneath the carpet pile and is configured to direct light from the panel through the carpet pile. A vehicle carpet so constructed can be used as a floor mat or as installed floor carpet.
In accordance with another aspect of the invention, there is provided a vehicle instrument panel utilizing an electroluminescent panel to provide downwardly-directed light. The instrument panel includes a lower surface that faces towards a floor area of the vehicle when installed, with the lower surface having a light-transmitting region. The electroluminescent panel is mounted within the instrument panel behind the lower surface at the light-transmitting region, and electroluminescent panel is configured to direct light from the panel through the light-transmitting region of the lower surface.
In accordance with yet another aspect of the invention, there is provided a vehicle interior illumination system that includes a light source, a switch assembly, and an electronic circuit for energizing the light source. The switch assembly includes at least one light-transmissive touch switch and an electroluminescent panel that is located behind the touch switch to provide back lighting of the touch switch upon energization by the electronic circuit. The electronic circuit is connected to the light source, touch switch, and electroluminescent panel, and is operable upon activation of the switch to energize the light source and to change energization of the electroluminescent panel.
In accordance with another aspect of the invention, there is provided a vehicle interior lighting and switch assembly, comprising a light-transmissive touch switch, a light source disposed behind the touch switch, and an electronic circuit connected to both the touch switch and light source. The light source comprises an electroluminescent panel and the circuit is operable upon activation of the touch switch to energize the electroluminescent panel to thereby provide area illumination through the touch switch. A vehicle lighting and switch assembly constructed in this manner can be used for dome lights and map lights within the vehicle.